A mysterious disease that’s killing deer across North America could spread to humans, scientists are warning.

Chronic Wasting Disease (CWD) is similar to Mad Cow’s disease, which eventually hopped over to humans to kill hundreds of people.

The CWD, a deadly neurological disorder known to some as a “zombie” disease, can be found in deer, elk, and moose. The affected animals are easy to identify when they’re near their death.

“They’re not hard to pick out at the end stage,” Dr. Mark Zabel told the New York Times. “They have a vacant stare, they have a stumbling gait, their heads are drooping, their ears are down, you can see thick saliva dripping from their mouths. It’s like a true zombie disease.”

NPR reported that the disease was first observed among captive mule deer in Colorado in 1967 and has since spread to wild herds in 24 states and some parts of Canada. It’s also been found in South Korea and Norway.

Humans were thought to be isolated from the disease but a new study from Canada indicated that the disease could very well affect humans.

The potential for CWD “to be transmitted to humans cannot be excluded,” reported The Health Products Food Branch of Health Canada (pdf).

“The most prudent approach is to consider that CWD has the potential to infect humans.”

The agency noted that experiments have shown that the disease, at least under specific experimental conditions, has the potential to cross the human species barrier. The experiment exposed 18 macaques to the disease in a variety of ways and resulted in many of the primates becoming infected. The study is ongoing.

Incubation times in the study ranged from 4.5 to 6.9 years, noted The Tyee. The macaques showed symptoms that included anxiety, ataxia, and tremors. One macaque lost a third of its body weight in six months.

“No one should consume animal products with a known prion disease,” said Stefanie Czub, a prion researcher with the Canadian Food Inspection Agency, who led the study.